Various devices, such as pulse oximetry devices, can measure some parameters of blood flow in a patient, such as heart rate and oxygen saturation of hemoglobin. Pulse oximetry devices are a non-invasive measurement device, typically employing solid-state lighting elements, such as light-emitting diodes (LEDs) or solid state lasers, to introduce light into the tissue of a patent. The light is then detected and analyzed to determine the parameters of the blood flow in the patient. However, conventional pulse oximetry devices typically only measure certain blood parameters, and are subject to patient-specific noise and inconsistencies which limits the accuracy of such devices.
Overview
A system for measuring a physiological parameter of blood in a patient is presented. The system includes a transmission module configured to emit a plurality of photon density waves into tissue of the patient from a plurality of modulated light sources. The system also includes a receiver module configured to detect characteristics of the plurality of photon density waves. The system also includes a processing module configured to identify characteristics of a pulsatile perturbation of the tissue based on the characteristics of the plurality of photon density waves, and identify a value of the physiological parameter based on at least the characteristics of the pulsatile perturbation of the tissue and the characteristics of the plurality of photon density waves.
A method of operating a system for measuring a physiological parameter of blood in a patient is also presented. The method includes emitting a plurality of photon density waves into tissue of the patient from a plurality of modulated light sources, and detecting characteristics of the plurality of photon density waves. The method also includes identifying characteristics of a pulsatile perturbation of the tissue based on the characteristics of the plurality of photon density waves, and identifying a value of the physiological parameter based on at least the characteristics of the pulsatile perturbation of the tissue and the characteristics of the plurality of photon density waves.
Another example system for measuring a physiological parameter of blood in a patient is also presented. The system includes a transmission module configured to emit a first modulated optical signal and a second modulated optical signal into tissue of the patient. The system also includes a receiver module configured to detect the first modulated optical signal and the second modulated optical signal propagated through the tissue during a pulsatile perturbation. The system also includes a processing module configured to process the detected first modulated optical signal and the detected second modulated optical signal to determine at least an amplitude and a phase delay of both the detected first modulated optical signal and the detected second modulated optical signal. The processing module is also configured to determine characteristics of the pulsatile perturbation of the tissue based on at least the amplitude and the phase delay of both the detected first modulated optical signal and the detected second modulated optical signal. The processing module is also configured to determine a value of the physiological parameter based on at least the characteristics of the pulsatile perturbation of the tissue and the amplitude and the phase delay of both the detected first modulated optical signal and the detected second modulated optical signal.